Numbering Resources

456-NXX Codes

Numbers within the 456 NPA are used to identify carrier-specific services. This is accomplished by providing carrier identification within the dialed digits of the E.164 number. More specifically, the prefix following 456 (456-NXX) identifies the carrier. Use of these numbers enables the proper routing of inbound international calls destined for these services into and between North American Numbering Plan area countries.

456-NXX codes are assigned according to the guidelines developed by the Industry Numbering Committee, which is sponsored by ATIS.